Genetic diversity affects testicular morphology in free-ranging lions (Panthera leo) of the Serengeti Plains and Ngorongoro Crater

Abstract

Reduced genetic variability is known to adversely affect ejaculate quality in inbred lions (Panthera leo) physically isolated in the Ngorongoro Crater compared with outbred lions inhabiting the adjacent Serengeti Plains in East Africa. This study compared the histomorphology of testicular biopsies from these two lion populations. Ngorongoro Crater lions had fewer (P < 0.05) seminiferous tubules with spermiogenesis and fewer (P < 0.05) spermatids per seminiferous tubular cross-section than Serengeti Plains lions, although seminiferous tubular diameter did not differ (P > 0.05) between populations. Interstitial areas were greater (P < 0.05) in Crater than in Plains lions, but no qualitative differences were evident, suggesting that proportionately less testicular area was occupied by seminiferous tubules in Crater lions. None of the lions in either population had evidence of testicular degeneration. Overall results suggest that inbred Crater lions have reduced spermiogenesis and less total seminiferous tubular area per testis. These data further support the premise that genetic homogeneity compromises reproductive traits in free-living, male African lions.

Plagues and adaptation: Lessons from the Felidae models for SARS and AIDS

“…One of the most detailed lion population studies is that of the Serengeti in Tanzania. This large panmictic population over 3000 individuals has provided many useful insights into lion pride structure, population dynamics, and transmission of infectious diseases (Gilbert et al, 1991;Hofmann-Lehmann et al, 1996;Muller-Graf et al, 1999;Munson et al, 1996;Packer et al, 2005). Long-term surveillance of lions in the Serengeti has not revealed any evidence of AIDS like illnesses, decreased viability, or decreased fecundity in this population where seroprevalence among adult lions is 100%.…”

Morphology of the female reproductive organs of the African lion (Panthera leo)

“…The effect of genetic diversity on testicular morphology in free‐ranging lions has also been published (Munson et al . ).…”

“…These include seminiferous tubules and testicular morphometry of adult African lions (de Barros et al 2006), sertoli cell index and spermatic reserves in adult captive African lions (de Barros et al 2007), cryptorchidism in the lion (Cohrs and Schneider 1936) and spermogram of African lions (Miya et al 2007). The effect of genetic diversity on testicular morphology in free-ranging lions has also been published (Munson et al 1996).…”

Normozoospermic versus teratozoospermic domestic cats: differential testicular volume, sperm morphometry, and subpopulation structure during epididymal maturation

“…Thus, these suboptimal sperm cells are incapable of penetrating the inner layer of the domestic cat zona pellucida9 and may ultimately result in infertility 10. There is strong evidence suggesting that a reduction in genetic diversity (inbreeding) contributes to the establishment of teratozoospermia, impairing spermatogenic function 1112. However, it has also been suggested that the causes of teratozoospermia are related to both endogenous (genetics and sexual hormone levels) and exogenous (environment, nutrition, and sexual activity) factors, or even related to stress level and health status 1314…”